Loss of the urinary bladder, most commonly due to total cystectomy for muscle invasive carcinoma of the bladder, bladder dysfunction or bladder injury resulting in contraction, stiffness, spasticity or failure to store or to empty urine in a suitable manner are presently being treated with replacement or augmentation of the urinary bladder with intestinal tissue. These operations all have in common either the creation of an intestinal urinary conduit which drains urine continuously into a plastic bag on the patient's abdominal wall or the creation of an internal pouch constructed of intestinal tissue which stores urine inside the patient's abdominal cavity, urine being released either by catheter or newly learned techniques of urination which rely on coordinated abdominal muscle contraction and pelvic muscle relaxation.
Although the simplest of these forms of urinary diversion, the Bricker intestinal conduit or "ileal loop", is a standard and commonly performed surgical procedure, it is the least desirable. A bag must be worn on the abdominal wall which leads to social withdrawal and undesirable change in body image and has been shown to lead to long term damage of the kidneys from infection, obstruction and urinary stone formation.
There has been great interest and activity, as an alternative to this kind of diversion, in the construction of internal urinary reservoirs made of long segments of intestinal tissue. These operations are difficult to perform and usually can be done only in specialized medical centers. There is a considerable increase in risk to the patient. Normal urination will only be possible in a very small select group of men in whom the pouch can be sewn to the natural urinary outlet. In the remaining group of patients, which includes all women, the reservoir must be emptied by intermittent self catheterization introduced by way of an opening in the abdominal wall or the perineum, In addition to the potential for operative complications, the long term effects of redirecting a long segment of intestine from the intestinal tract to a reservoir which provides continuous contact with urine has yet to be determined. Disorders of digestive motility and absorption are common, absorption of urinary waste products through the intestinal wall is common, and the potential for development of cancer in the bowel segment in continuous contact with urine has been recognized, although the extent to which this may become a problem is yet unknown.
Although the use of extensive intestinal substitution and augmentation of the urinary bladder has become popular and safe in the hands of very specialized urological surgeons in a few national medical centers, the long term safety and efficacy remains to be determined, and there is every reason to believe that unexpected difficulties may arise within the next ten years following such reconstruction. There is thus a great need for a totally artificial urinary bladder which would allow patients to undergo complete replacement of the bladder without removal of any segment of the digestive tract.
Sowinski, French Patent No. 2,116,838, discloses an artificial bladder for implantation into the bladder's natural position and for connection to the two ureters and to the urethra of a patient. This bladder comprises a hollow elastic ball which can be elastically deformed to an inflated or to a deflated position under the presence of an auxiliary fluid, surrounding a deformable reception chamber for urine; a system of three internal valves, one of which operates in a direction opposite that of the other two; and a device to control the valves thereby controlling the auxiliary fluid. This bladder is complicated and relatively unreliable.
Chevallet, U.S. Pat. No. 3,953,897, discloses an implantable artificial bladder comprising a flexible plastic pouch which relies upon the internal tensions of the pouch wall in combination with external forces, including the force of the patient's abdominal muscles, to empty the pouch completely and rapidly. Chevallet relied upon the peristaltic effect of the ureter to prevent urine from flowing backwards. However, the combination of the internal tension of the artificial bladder wall and the external pressure of the patient's abdominal muscles could likely be greater than the peristaltic pressure of the ureter, particularly upon the discharging of contents of the bladder and therefore could cause urine to flow backwards through the ureters toward the kidneys.
Additionally, the reference bladder chamber is of one piece construction. The configuration of the bladder chamber results in internal capacity that becomes practically negligible upon emptying but not completely empty and necessarily comprises a fold of the chamber, inherently forming a void. The retention of urine resulting from any residual volume can promote infection, disease, or the formation of lithiases, calculi or other concretions.
Rey et al, U.S. Pat. No. 4,311,659, disclose a process for the manufacture of perfect surface state organ prostheses which can be used in the manufacture of artificial bladders and thereby may prevent the formation of various concretions. The one-piece reference bladder, however, in the empty position has a transverse cross-section in the form of two W's lying in opposite direction resulting in residual volume and therefore in retained fluid. Furthermore, backpressure of the Rey et al bladder is such that it preferably requires a urine non-return valve.
Freier, Federated Republic of Germany Patent No. 2,655,034, discloses an artifical bladder comprised of stiff plastics and valves to prevent the return flow of urine through the ureters and toward the kidneys.
Copending, commonly assigned U.S. patent application Ser. No. 07/279,600, filed Dec. 5, 1988, discloses a hard shell constant force stored energy implantable artificial bladder system. A stored energy device is relied upon to empty the bladder, and the disphragm forming the inner chamber folds upon itself.
It is an object of the present invention to provide an implantable artifical bladder soft system which has the compliance, the resistance or the spring rate of a normal bladder and therefore is capable of being completely emptied, which can be filled with only pressure equivalent to the normal peristaltic pressure of normal ureters, which provides virtually no backpressure through the ureter(s) until the bladder is completely full, and which can be discharged either with abdominal pressure, gravity, external pressure or a combination thereof, thereby allowing a patient to function in a nearly normal manner after the removal or the dysfunction of the natural bladder
It is a further object of the present invention to provide a method for the collection of, the storage of or the discharge of biological fluids that will allow the patient to function in a nearly normal manner as well.
A primary advantage of the present invention is that the implantable artificial bladder can be emptied completely. A further advantage is that the pressure exerted by the implantable artificial bladder and/or the pressure required to fill or to empty the implantable artificial bladder can be tailored to the individual patient to assure that the back pressure exerted by the implantable artifical bladder does not exceed the peristaltic pressure of the patient's ureter. This assures that there will be no resultant backflow of urine through the ureter(s) to the kidney(s) which would result in damage to those body parts. A still further advantage is that the patient himself can control the discharge of urine by applying the pressure needed to empty the bladder at will.